Miller revived an observation made by Scottish Philosopher William Hamilton. After throwing marbles on a floor, “you will find it difficult to view at once more than six, or seven at most, without confusion.”

More items, however, Hamilton noted can be remembered when they are “chunked.”

One can remember long strings of numbers, letters, or words when they are reconstructed into meaningful patterns, also known as “memory pegs.”

One that is familiar to most of us concerns the position of the planets in relations to the sun, which is remembered by the mnemonic aid “My Very Educated Mother Just Sent Us Nine Pizzas.” This sequence reminds us of the planetary order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. (Before you ask, I haven’t abandoned Pluto just yet.)

Consider Mozart’s memorization of the Miserere, written more than a century earlier by the Italian composer Gregorio Allegri.

In 1770, while in his early teens, Mozart visited the Vatican’s Sistine Chapel and heard this choral work performed on only two occasions. He then sat down and wrote out the entire score from memory. We know this because only three copies of the score existed at the time and its owner, the Vatican, forbade any publication. Thus, Mozart had no source for re-creating the score other than his own recall of the performances he had attended. Now that the score is freely available, Mozart’s accomplishment seems less remarkable. Musicians have told me that the Miserere is harmonically quite conventional for the period. Anyone who shared Mozart’s familiarity with similar musical forms would not find it a great challenge to chunk large parts of the work around these standard structures.

A further addition to the story comes from John Sloboda’s book The Musical Mind. “Mozart’s feat of memory does not involve inexplicable processes which set him apart from other musicians,” he writes. “Rather it distinguished him as someone whose superior knowledge and skill allow him to accomplish something rapidly and supremely confidently which most of us can do, albeit less efficiently, and on a smaller scale.”

The Memory Palace is a form of chunking, which propelled Joshua Foer to the world Memory Champion. The concept is believed to be first suggested by the Greek poet, Simonides of Ceos who suggested, as Restak tells us, “an imaginary walk through one’s own house or town square. At selected locations along the walk, Simonides would conjure up a vivid mental picture of the location to remind him of a point he wished to make in a speech.”

Basically link what you want to remember with a specific location you know well and a vivid image. Why a vivid image?

The reason comes from Ad Herennium, which dates to 82 B.C. The unknown author writes:

[O]rdinary things easily slip from the memory while the striking and the novel stay longer in the mind. We ought then to set up images that can adhere longest in memory. And we shall do so if we establish similitudes as striking as possible; if we set up images that are not many or vague but active; if we assign to them exceptional beauty or singular ugliness.

In their book, (The Memory Book) Lorrayne and Lucas give several examples of the use of stark images to provide memory clues to overcome absentmindedness. For instance, if you want to be sure you don’t leave your umbrella at the office, they suggest the following “ridiculous” image: “As you arrive and put your umbrella away, associate it to the first thing you see or do as you’re leaving the office. If you ride in an elevator picture an umbrella operating it.”

The brain weaves together the right and left hemispheres into one total experience.

Visualization exercises strengthen the powers of the right hemisphere. And when you bring the left hemisphere into play, the integration between the hemispheres is enhanced.

Intensely studying art can increase the powers of visual perception, something that was well-known to the ancients, who used art to meditate, focus, and hopefully further their quest towards enlightenment.

Asian art, especially Tibetan Buddhist paintings, was created to enhance the powers of visual perception. Buddhist devotees intensely studied the paintings until they could envision the images down to the smallest detail. They believed this act of visualization and intense concentration cleansed and prepared their minds to assume the attributes and wisdom of the beings portrayed in the paintings.

Roberta Smith, a New York Times art critic, said of these Tibetan paintings, “These images are visual exercises of the highest order. Each time you look at them, you see and understand more. . . . They were often tools that helped develop the powers of meditation basic to enlightenment.”

Visual Chess

Restak suggests you do the following exercise to improve your visual acuity by playing “visual chess.”

Most chess masters can manage a game of ‘mental chess’; some of the great masters of the past could play several opponents simultaneously while blindfolded. … Although it’s less demanding than blindfold chess, you’ll find it challenging.

Read into a tape recorder the first dozen moves of a famous chess match. My favorite is the game played in 1858 by American chess prodigy Paul Morphy against Duke Karl Brunswick and Count Isouard during an intermission in the royal box at the opera house in Paris. Whichever game you choose, read the moves slowly and distinctly with a five-second pause between each move. (For the first few efforts, you probably won’t have to read more than a dozen moves.) Then set up the chessboard and begin.

Turn on the tape recorder and mentally make the first move by white, followed by black’s response. Imagine the resulting position of the pieces on the board. Continue the moves until you experience a slight lack of clarity or doubt about the position of the pieces. Focus as keenly as possible. See the pieces in your mind. When you reach the point where you can’t image the board and the position of the pieces, open your eyes and move the pieces until you reach the position where you began to lose clarity. (The best arrangement of all is to have someone moving the pieces as you call out each move; thus, upon opening your eyes, you immediately encounter the exact position where your imaging faltered.) When you can once again establish a clear image of the position, close your eyes again and continue.

If you’re not into chess, you can accomplish the same thing by attempting to complete a crossword puzzle without resorting to pencil or pen.

As you come up with the correct words, visualize them on the grid and retain them in your memory. See how far you can get before you have to stop. Since this is a test of visualization rather than a test of your talent for solving crossword puzzles, have the solution readily at hand so you can mentally fill in the missing words and go on with visualizing.

These exercises are designed to prime the frontal lobes, which help with concentration and focus, the visual association areas, and the hippocampus and its attendant connections (which govern memory). Over time, disciplined practice can yield some very interesting and worthwhile improvements.